It's not the 'what', but the 'how': Exploring the role of debt in natural resource (un)sustainability

A debt-based economy cannot survive without economic growth. However, if private debt consistently grows faster than GDP, the consequences are financial crises and the current unprecedented level of global debt. This policy dilemma is aggravated by the lack of analyses factoring the impact of debt-growth cycles on the environment. What is really the relationship between debt and natural resource sustainability, and what is the role of debt in decoupling economic growth from natural resource availability? Here we present a conceptual Agent-Based Model (ABM) that integrates an environmental system into an ABM representation of Steve Keen’s debt-based economic models. Our model explores the extent to which debt-driven processes, within debt-based economies, enhance the decoupling between economic growth and the availability of natural resources. Interestingly, environmental and economic collapse in our model are not caused by debt growth, or the debt-based nature of the economic system itself (i.e. the ‘what’), but rather, these are due to the inappropriate use of debt by private actors (i.e. the ‘how’). Firms inappropriately use bank credits for speculative goals–rather than production-oriented ones–and for exponentially increasing rates of technological development. This context creates temporal mismatches between natural resource growth and firms’ resource extraction rates, as well as between economic growth and the capacity of the government to effectively implement natural resource conservation policies. This paper discusses the extent to which economic growth and the availability of natural resources can be re-coupled through a more sustainable use of debt, for instance by shifting mainstream banking forces to partially support environmental conservation as well as economic growth.债务型经济体若无经济增长则无法存续。然而，若私人债务增速持续高于国内生产总值（Gross Domestic Product, GDP），则会引发金融危机，同时推高当前全球债务的空前规模。当前的政策困境因现有分析未纳入债务-增长周期对环境的影响而进一步加剧。债务与自然资源可持续性之间究竟存在何种关联？债务在实现经济增长与自然资源供给脱钩的过程中又扮演着怎样的角色？本文提出一款概念性基于智能体模型（Agent-Based Model，ABM），将环境系统融入史蒂夫·基恩（Steve Keen）债务型经济模型的ABM建模框架中。本模型探究了在债务型经济体中，债务驱动进程在多大程度上强化了经济增长与自然资源供给之间的脱钩关系。值得注意的是，本模型中的环境与经济崩溃并非由债务增长或经济系统本身的债务属性（即“是什么”）所引发，而是源于私人主体对债务的不当使用（即“如何使用”）。企业将银行信贷不当用于投机目的而非生产导向用途，同时以指数级速度提升技术研发速率。该情形导致自然资源增长与企业资源开采速率之间出现时间错配，同时也造成经济增长与政府有效落实自然资源保护政策的能力之间的失衡。本文探讨了通过更可持续的债务使用方式——例如推动主流银行业将部分资源转向支持自然资源保护与经济增长——可在多大程度上实现经济增长与自然资源供给的重新挂钩。